In recent years, demand for lithium secondary cells and other secondary cells has been increasing for portable information terminals, portable electronic devices, and other portable terminals and also various other applications such as small-size power storage devices for household use, two-wheel motor vehicles, electric vehicles, hybrid electric vehicles, etc. Along with the growth in applications, further improvements in safety of secondary cells is being demanded. To secure safety, the method of preventing leakage of liquids and the method of using solid electrolytes instead of organic solvent electrolytes—which are highly flammable and are high in risk of causing fires when leaking—are effective.
For example, Patent Document 1 discloses an all-solid state secondary cell which is configured by using a solid electrolyte constituted by sulfide glass and/or sulfide glass ceramic comprised of Li2S and P2S5.